root/webserver/example/freeRTOS/Demo/Common/ethernet/lwIP/netif/ppp/pap.c

/*****************************************************************************
* pap.c - Network Password Authentication Protocol program file.
*
* Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
* portions Copyright (c) 1997 by Global Election Systems Inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 03-01-01 Marc Boucher <marc@mbsi.ca>
*   Ported to lwIP.
* 97-12-12 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
*       Original.
*****************************************************************************/
/*
 * upap.c - User/Password Authentication Protocol.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "ppp.h"
#include "auth.h"
#include "pap.h"
#include "pppdebug.h"


#if PAP_SUPPORT > 0

/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
/*
 * Protocol entry points.
 */
static void upap_init (int);
static void upap_lowerup (int);
static void upap_lowerdown (int);
static void upap_input (int, u_char *, int);
static void upap_protrej (int);

static void upap_timeout (void *);
static void upap_reqtimeout (void *);
static void upap_rauthreq (upap_state *, u_char *, int, int);
static void upap_rauthack (upap_state *, u_char *, int, int);
static void upap_rauthnak (upap_state *, u_char *, int, int);
static void upap_sauthreq (upap_state *);
static void upap_sresp (upap_state *, u_char, u_char, char *, int);




/******************************/
/*** PUBLIC DATA STRUCTURES ***/
/******************************/
struct protent pap_protent = {
    PPP_PAP,
    upap_init,
    upap_input,
    upap_protrej,
    upap_lowerup,
    upap_lowerdown,
    NULL,
    NULL,
#if 0
    upap_printpkt,
    NULL,
#endif
    1,
    "PAP",
#if 0
    NULL,
    NULL,
    NULL
#endif
};

upap_state upap[NUM_PPP];               /* UPAP state; one for each unit */



/***********************************/
/*** PUBLIC FUNCTION DEFINITIONS ***/
/***********************************/
/*
 *  Set the default login name and password for the pap sessions
 */
void upap_setloginpasswd(int unit, const char *luser, const char *lpassword)
{
        upap_state *u = &upap[unit];
        
        /* Save the username and password we're given */
        u->us_user = luser;
        u->us_userlen = strlen(luser);
        u->us_passwd = lpassword;
        u->us_passwdlen = strlen(lpassword);
}


/*
 * upap_authwithpeer - Authenticate us with our peer (start client).
 *
 * Set new state and send authenticate's.
 */
void upap_authwithpeer(int unit, char *user, char *password)
{
        upap_state *u = &upap[unit];
        
        UPAPDEBUG((LOG_INFO, "upap_authwithpeer: %d user=%s password=%s s=%d\n",
                                unit, user, password, u->us_clientstate));
        
        upap_setloginpasswd(unit, user, password);

        u->us_transmits = 0;
        
        /* Lower layer up yet? */
        if (u->us_clientstate == UPAPCS_INITIAL ||
                        u->us_clientstate == UPAPCS_PENDING) {
                u->us_clientstate = UPAPCS_PENDING;
                return;
        }
        
        upap_sauthreq(u);                       /* Start protocol */
}


/*
 * upap_authpeer - Authenticate our peer (start server).
 *
 * Set new state.
 */
void upap_authpeer(int unit)
{
        upap_state *u = &upap[unit];
        
        /* Lower layer up yet? */
        if (u->us_serverstate == UPAPSS_INITIAL ||
                        u->us_serverstate == UPAPSS_PENDING) {
                u->us_serverstate = UPAPSS_PENDING;
                return;
        }
        
        u->us_serverstate = UPAPSS_LISTEN;
        if (u->us_reqtimeout > 0)
                TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);
}



/**********************************/
/*** LOCAL FUNCTION DEFINITIONS ***/
/**********************************/
/*
 * upap_init - Initialize a UPAP unit.
 */
static void upap_init(int unit)
{
        upap_state *u = &upap[unit];

        UPAPDEBUG((LOG_INFO, "upap_init: %d\n", unit)); 
        u->us_unit = unit;
        u->us_user = NULL;
        u->us_userlen = 0;
        u->us_passwd = NULL;
        u->us_passwdlen = 0;
        u->us_clientstate = UPAPCS_INITIAL;
        u->us_serverstate = UPAPSS_INITIAL;
        u->us_id = 0;
        u->us_timeouttime = UPAP_DEFTIMEOUT;
        u->us_maxtransmits = 10;
        u->us_reqtimeout = UPAP_DEFREQTIME;
}

/*
 * upap_timeout - Retransmission timer for sending auth-reqs expired.
 */
static void upap_timeout(void *arg)
{
        upap_state *u = (upap_state *) arg;
        
        UPAPDEBUG((LOG_INFO, "upap_timeout: %d timeout %d expired s=%d\n", 
                                u->us_unit, u->us_timeouttime, u->us_clientstate));
        
        if (u->us_clientstate != UPAPCS_AUTHREQ)
                return;
        
        if (u->us_transmits >= u->us_maxtransmits) {
                /* give up in disgust */
                UPAPDEBUG((LOG_ERR, "No response to PAP authenticate-requests\n"));
                u->us_clientstate = UPAPCS_BADAUTH;
                auth_withpeer_fail(u->us_unit, PPP_PAP);
                return;
        }
        
        upap_sauthreq(u);               /* Send Authenticate-Request */
}


/*
 * upap_reqtimeout - Give up waiting for the peer to send an auth-req.
 */
static void upap_reqtimeout(void *arg)
{
        upap_state *u = (upap_state *) arg;
        
        if (u->us_serverstate != UPAPSS_LISTEN)
                return;                 /* huh?? */
        
        auth_peer_fail(u->us_unit, PPP_PAP);
        u->us_serverstate = UPAPSS_BADAUTH;
}


/*
 * upap_lowerup - The lower layer is up.
 *
 * Start authenticating if pending.
 */
static void upap_lowerup(int unit)
{
        upap_state *u = &upap[unit];
        
        UPAPDEBUG((LOG_INFO, "upap_lowerup: %d s=%d\n", unit, u->us_clientstate));
        
        if (u->us_clientstate == UPAPCS_INITIAL)
                u->us_clientstate = UPAPCS_CLOSED;
        else if (u->us_clientstate == UPAPCS_PENDING) {
                upap_sauthreq(u);       /* send an auth-request */
        }
        
        if (u->us_serverstate == UPAPSS_INITIAL)
                u->us_serverstate = UPAPSS_CLOSED;
        else if (u->us_serverstate == UPAPSS_PENDING) {
                u->us_serverstate = UPAPSS_LISTEN;
                if (u->us_reqtimeout > 0)
                        TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);
        }
}


/*
 * upap_lowerdown - The lower layer is down.
 *
 * Cancel all timeouts.
 */
static void upap_lowerdown(int unit)
{
        upap_state *u = &upap[unit];
        
        UPAPDEBUG((LOG_INFO, "upap_lowerdown: %d s=%d\n", unit, u->us_clientstate));
        
        if (u->us_clientstate == UPAPCS_AUTHREQ)        /* Timeout pending? */
                UNTIMEOUT(upap_timeout, u);             /* Cancel timeout */
        if (u->us_serverstate == UPAPSS_LISTEN && u->us_reqtimeout > 0)
                UNTIMEOUT(upap_reqtimeout, u);
        
        u->us_clientstate = UPAPCS_INITIAL;
        u->us_serverstate = UPAPSS_INITIAL;
}


/*
 * upap_protrej - Peer doesn't speak this protocol.
 *
 * This shouldn't happen.  In any case, pretend lower layer went down.
 */
static void upap_protrej(int unit)
{
        upap_state *u = &upap[unit];
        
        if (u->us_clientstate == UPAPCS_AUTHREQ) {
                UPAPDEBUG((LOG_ERR, "PAP authentication failed due to protocol-reject\n"));
                auth_withpeer_fail(unit, PPP_PAP);
        }
        if (u->us_serverstate == UPAPSS_LISTEN) {
                UPAPDEBUG((LOG_ERR, "PAP authentication of peer failed (protocol-reject)\n"));
                auth_peer_fail(unit, PPP_PAP);
        }
        upap_lowerdown(unit);
}


/*
 * upap_input - Input UPAP packet.
 */
static void upap_input(int unit, u_char *inpacket, int l)
{
        upap_state *u = &upap[unit];
        u_char *inp;
        u_char code, id;
        int len;
        
        /*
         * Parse header (code, id and length).
         * If packet too short, drop it.
         */
        inp = inpacket;
        if (l < UPAP_HEADERLEN) {
                UPAPDEBUG((LOG_INFO, "pap_input: rcvd short header.\n"));
                return;
        }
        GETCHAR(code, inp);
        GETCHAR(id, inp);
        GETSHORT(len, inp);
        if (len < UPAP_HEADERLEN) {
                UPAPDEBUG((LOG_INFO, "pap_input: rcvd illegal length.\n"));
                return;
        }
        if (len > l) {
                UPAPDEBUG((LOG_INFO, "pap_input: rcvd short packet.\n"));
                return;
        }
        len -= UPAP_HEADERLEN;
        
        /*
         * Action depends on code.
         */
        switch (code) {
        case UPAP_AUTHREQ:
                upap_rauthreq(u, inp, id, len);
                break;
        
        case UPAP_AUTHACK:
                upap_rauthack(u, inp, id, len);
                break;
        
        case UPAP_AUTHNAK:
                upap_rauthnak(u, inp, id, len);
                break;
        
        default:                                /* XXX Need code reject */
                break;
        }
}


/*
 * upap_rauth - Receive Authenticate.
 */
static void upap_rauthreq(
        upap_state *u, 
        u_char *inp, 
        int id,
        int len
)
{
        u_char ruserlen, rpasswdlen;
        char *ruser, *rpasswd;
        int retcode;
        char *msg;
        int msglen;
        
        UPAPDEBUG((LOG_INFO, "pap_rauth: Rcvd id %d.\n", id));
        
        if (u->us_serverstate < UPAPSS_LISTEN)
                return;
        
        /*
         * If we receive a duplicate authenticate-request, we are
         * supposed to return the same status as for the first request.
         */
        if (u->us_serverstate == UPAPSS_OPEN) {
                upap_sresp(u, UPAP_AUTHACK, id, "", 0); /* return auth-ack */
                return;
        }
        if (u->us_serverstate == UPAPSS_BADAUTH) {
                upap_sresp(u, UPAP_AUTHNAK, id, "", 0); /* return auth-nak */
                return;
        }
        
        /*
         * Parse user/passwd.
         */
        if (len < sizeof (u_char)) {
                UPAPDEBUG((LOG_INFO, "pap_rauth: rcvd short packet.\n"));
                return;
        }
        GETCHAR(ruserlen, inp);
        len -= sizeof (u_char) + ruserlen + sizeof (u_char);
        if (len < 0) {
                UPAPDEBUG((LOG_INFO, "pap_rauth: rcvd short packet.\n"));
                return;
        }
        ruser = (char *) inp;
        INCPTR(ruserlen, inp);
        GETCHAR(rpasswdlen, inp);
        if (len < rpasswdlen) {
                UPAPDEBUG((LOG_INFO, "pap_rauth: rcvd short packet.\n"));
                return;
        }
        rpasswd = (char *) inp;
        
        /*
         * Check the username and password given.
         */
        retcode = check_passwd(u->us_unit, ruser, ruserlen, rpasswd,
                           rpasswdlen, &msg, &msglen);
        BZERO(rpasswd, rpasswdlen);
        
        upap_sresp(u, retcode, id, msg, msglen);
        
        if (retcode == UPAP_AUTHACK) {
                u->us_serverstate = UPAPSS_OPEN;
                auth_peer_success(u->us_unit, PPP_PAP, ruser, ruserlen);
        } else {
                u->us_serverstate = UPAPSS_BADAUTH;
                auth_peer_fail(u->us_unit, PPP_PAP);
        }
        
        if (u->us_reqtimeout > 0)
                UNTIMEOUT(upap_reqtimeout, u);
}


/*
 * upap_rauthack - Receive Authenticate-Ack.
 */
static void upap_rauthack(
        upap_state *u,
        u_char *inp,
        int id,
        int len
)
{
        u_char msglen;
        char *msg;
        
        UPAPDEBUG((LOG_INFO, "pap_rauthack: Rcvd id %d s=%d\n", id, u->us_clientstate));
        
        if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
                return;
        
        /*
         * Parse message.
         */
        if (len < sizeof (u_char)) {
                UPAPDEBUG((LOG_INFO, "pap_rauthack: rcvd short packet.\n"));
                return;
        }
        GETCHAR(msglen, inp);
        len -= sizeof (u_char);
        if (len < msglen) {
                UPAPDEBUG((LOG_INFO, "pap_rauthack: rcvd short packet.\n"));
                return;
        }
        msg = (char *) inp;
        PRINTMSG(msg, msglen);
        
        u->us_clientstate = UPAPCS_OPEN;
        
        auth_withpeer_success(u->us_unit, PPP_PAP);
}


/*
 * upap_rauthnak - Receive Authenticate-Nakk.
 */
static void upap_rauthnak(
        upap_state *u,
        u_char *inp,
        int id,
        int len
)
{
        u_char msglen;
        char *msg;
        
        UPAPDEBUG((LOG_INFO, "pap_rauthnak: Rcvd id %d s=%d\n", id, u->us_clientstate));
        
        if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
                return;
        
        /*
         * Parse message.
         */
        if (len < sizeof (u_char)) {
                UPAPDEBUG((LOG_INFO, "pap_rauthnak: rcvd short packet.\n"));
                return;
        }
        GETCHAR(msglen, inp);
        len -= sizeof (u_char);
        if (len < msglen) {
                UPAPDEBUG((LOG_INFO, "pap_rauthnak: rcvd short packet.\n"));
                return;
        }
        msg = (char *) inp;
        PRINTMSG(msg, msglen);
        
        u->us_clientstate = UPAPCS_BADAUTH;
        
        UPAPDEBUG((LOG_ERR, "PAP authentication failed\n"));
        auth_withpeer_fail(u->us_unit, PPP_PAP);
}


/*
 * upap_sauthreq - Send an Authenticate-Request.
 */
static void upap_sauthreq(upap_state *u)
{
        u_char *outp;
        int outlen;
        
        outlen = UPAP_HEADERLEN + 2 * sizeof (u_char) 
                        + u->us_userlen + u->us_passwdlen;
        outp = outpacket_buf[u->us_unit];
        
        MAKEHEADER(outp, PPP_PAP);
        
        PUTCHAR(UPAP_AUTHREQ, outp);
        PUTCHAR(++u->us_id, outp);
        PUTSHORT(outlen, outp);
        PUTCHAR(u->us_userlen, outp);
        BCOPY(u->us_user, outp, u->us_userlen);
        INCPTR(u->us_userlen, outp);
        PUTCHAR(u->us_passwdlen, outp);
        BCOPY(u->us_passwd, outp, u->us_passwdlen);
        
        pppWrite(u->us_unit, outpacket_buf[u->us_unit], outlen + PPP_HDRLEN);
        
        UPAPDEBUG((LOG_INFO, "pap_sauth: Sent id %d\n", u->us_id));
        
        TIMEOUT(upap_timeout, u, u->us_timeouttime);
        ++u->us_transmits;
        u->us_clientstate = UPAPCS_AUTHREQ;
}


/*
 * upap_sresp - Send a response (ack or nak).
 */
static void upap_sresp(
        upap_state *u,
        u_char code, 
        u_char id,
        char *msg,
        int msglen
)
{
        u_char *outp;
        int outlen;
        
        outlen = UPAP_HEADERLEN + sizeof (u_char) + msglen;
        outp = outpacket_buf[u->us_unit];
        MAKEHEADER(outp, PPP_PAP);
        
        PUTCHAR(code, outp);
        PUTCHAR(id, outp);
        PUTSHORT(outlen, outp);
        PUTCHAR(msglen, outp);
        BCOPY(msg, outp, msglen);
        pppWrite(u->us_unit, outpacket_buf[u->us_unit], outlen + PPP_HDRLEN);
        
        UPAPDEBUG((LOG_INFO, "pap_sresp: Sent code %d, id %d s=%d\n", 
                                code, id, u->us_clientstate));
}

#if 0
/*
 * upap_printpkt - print the contents of a PAP packet.
 */
static int upap_printpkt(
        u_char *p,
        int plen,
        void (*printer) (void *, char *, ...),
        void *arg
)
{
        (void)p;
        (void)plen;
        (void)printer;
        (void)arg;
        return 0;
}
#endif

#endif /* PAP_SUPPORT */